Mi Redmi - charges for service in warranty

sir,
i bought READMI * mobile on **-**-**** from poorvika mobiles
within three month i service the phone * times due to hanging problem
now yesterday i went readmi service centre in padi for service my phone
in yellow patches on display, they said the phone was drop in water,
so there is no warranty if you want change the display you must pay, then i said
iam not drop my phone in water hence you return my phone, but they said you paid Rs.*** for service charge, i said within warranty how can you claim service charge they told if you give the money we will return the phone other wise not return the phone then i paid the money and receive the phone here iam attach my all documents, if you not return the money i will go to consumer court and also tell the truth to the people of india by media and online services
expecting your reply immediately

regards
n.chandrasekaran
ncs****@gmail.com